Multicolor cinematograph film material



NV- 19, 1929. J. E. THORNTON 1,736,556

MULTICOLOR GINEMATOGRAPH FILM MATERIAL File@l Deo. '7. 1925 reen. dra/yen )//ow Fig@ Fig@ f FM.

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Patented Nov. 19, 1929 UNITED STATES PATENT OFFICE JOHN EDWARD THORNTON, OF WEST HAMPSTEAD, LONDON, ENGLAND, ASSIGNOB TO JOHN OWDEN OBRIEN, 0F MANCHESTER, ENGLAND MULTICOLOR CINEMATOGRAPH FILM MATERIA`L- Application led December 7, 1925, Serial No. 73,948, and in Great Britain December 1.9, 1924.

This invention relates to the manufacture of a special form of double width sensitized material for the production of multi-color positive cinematograph films.

According to the invention the film material comprises a transparent support equal in width to two picture areas, a sensitized panchromatic gelatine-silver bromid emulsion layer upon one side of the transparent support and a non-sensitized multi-color eolloid layer arranged in two half widths upon the other side 'of the transparent support each half width comprising a mosaic pattern filter screen in two colors.

The invention will be described with reference to the accompanying drawings Fig. l is a transverse section greatly enlarged in depth through a double width negative film material made according to the invention the picture being .photographed through the color screen and Celluloid base as shown by the arrow A.

Figs. 2, 3 and 4 are plan views greatly en-L larged of portions of the four colored gelatine adjacent to the centre line'of the double width strip.

Figs. 5, 6 and 7 are similar plan views of a double width strip having a three color color screen.

Fig. 8 is a plan view of the double width strip showing the coating of sensitive gelatino silver bromid panchromatic emulsion thereon.

The film base or support consists of a strip oftransparent waterproof material such as celluloid, cellulose-acetate, or the like of double standard width (Fig. 8) and approximately rather less than half standard film base thickness.

This transparent support is coated upon both sides with an adhesive substratum of the usual kind to ensure perfectv adherence thereto of the next layer.

Upon one side of the iilm, superimposed upon the substratum, is applied a layer of gelatine or other suitable colloid, upon or in which is formed a pair of color-groups of lines or dots (Figs. 2-73 staining the gelatine with yes of two mordanted colors arranged in the form of two diierent pairs each containing two colors, the

by printing or l `chromatic gelatino-silver-bromid emulsion of the usual tine-grain type (Fig. l).

The multi-color gelatine layerk for fourcolor pictures consists of an immense number of exceedingly fine colored areas in the form of dots, lines, or mosaic pattern (Figs. .f2-4) disposed in two groups (each of twocolors) side-by-side upon the two halves of the double-width film strip. The dots, lines, or other form of fine colored areas are placed in close juxtaposition with their two colors intermixed, preferably in equal proportions of each, and one pair of colors is placed upon one strip and the other pair upon the other strip of the double-with, and the colors of each pair in the group are different.

The colors used for a four-color set are preferably crimson-red and blue-green for one half the film, and blue-violet and orangeyellow for the other half. These form one complete color-group. Each half of the double-width film therefore contains its own complementary color, and the two halves are also complementary to each other. This particular arrangement however is not necessarily a hard and fast rule, though it is preferred.

The multi-color gelatine layer for threecolors is of a similar character consisting of fine dots, lines, or mosaic pattern (Figs. 5-7 but the colors comprise only crimson-re bluegreen, and blue-violet, and are therefore only semi-complementary. They are arranged in\ two groups, one upon each half of the double-width film as in the preceding example, but one of the colors is duplicated upon each half in order to fill the fourth space. For example, one half-Width may have a half-group of crimson-red and bluegreen, and the other a half-group of blueviolet and blue-green.

In making pictures by means of this filmgraduations (preferably black silver) are formed in one layer and multi-colored posimaterial negative-images in monochrome tive-images in the other layer, the negativeimages being used only for the temporary purpose of printing and roducing the permanent positive-images, a er which the temporary negative-images are removed from the iilm'or plate, leaving thereon only the' pair of multi-color-mosaic transparent positives.

After these black-silver primary images have been printed, developed and finished as described in Serial No. 73,947 filed December 7 1925, the second step consists in sensitizing the multi-color gelatine layer upon the other side of the film before the final multicolor images can be produced.

This sensitizing process is conveniently carried out in the film-printing factory where the prints are made and therefore forms no part of the actual film manufacture, but to make the entire processes of sensitizing quite clear this sensitizing process will now be de scribed.

The best method of rendering the multicolored gelatine la er sensitive to light is by treatin it to a bath of one of the bichromate salts o the usual type and strength (applied to the multi-colored gelatine layer only) by means of coating rollers until the layer is completely saturated with the bichromate solution, after which the film is again dried.

What I claim as my invention and desire to protect by Letters Patent is 1. A double-width multi-color positive film material comprising a transparent support equal in width to two picture areas, a sensitized v panchromatic gelatine-silver bromid emulsion layer upon one side of the transparent support and a non-sensitized multicolor colloid layer arranged in two half- Widths upon the other side of the transparent su port each half width comprising a mosalc pattern filter screenin two colors.

2. A double-width four color positive film material comprising a transparent support of double picture area, two different kinds of image layers thereon, one layer being ready sensitized and consisting of a panchromatic gelatino-silver-bromid emulsion, the other layer being non-sensitized and consisting of interspersed mosaic pattern of colored colloid, the two different kinds of layers being formed upon and attached to opposite sides of the transparent support the multi-colored layer being formed as two parallel stripes each of two colors the colors of one being different from the colors of the other.

3. An improved photographic film or plate material adapted to produce mult-i-color transparent positives in two parts, comprising in its construction:-(A) a double-area transparent support having a surface area equal to two picture-areas; (B) a double-area layer of temporary monochrome-image-producing gelatino-emulsion of silver-salts u on one side of the support; and (C) a douillearea layer of permanent multi-color-imageproducing colloid, in the form of two colloid mosaics, one mosaic comprising two colors and the other mosaic comprising two other colors; the two differently-colored colloid mosaics being adapted to produce a complementary pair of half-pictures which when superimposed by -cementing or combined by proj ection will produce a complete picture upon the other'side of the support. 

